Method and apparatus for applying and treating varnish



Feb. 12, 1929. 1,702,043

E. L. ELLIOTT METHOD AND APPARATUS FOR APPLYING AND TREATING VARNISH Filed Sept. 15, 1925 CELLULOSE VARNISH v QMUMWOZ Patented Feb. 12, 1929.

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lhis invention relates to improvements in methods of applying varnish coats to articles' of manufacture and drying the varnish coats to render the surfaces of the coats free from tackiness, and to an apparatus of special construction for practising the method. The invention will be described for purposes of illustration in connection with the manufacture of patent leather, it being understood, however, that the invention in its various important features and characteristics may have other applications and uses.

In the manufacture of patent leather in accordance with methods commonly employed in this country, a specially prepared varnish is applied to the surface of prepared skins or hides, stretched upon frames, by means of hand brushes manipulated to rub the varnish material thoroughly into contact with the surface of each piece of leather. After this coat has been allowed to dry several hours, a second coat is applied and thoroughl spread over the surface of the first coat by hand-operated brushes, the operation requiring the exercise of considerable skill and care in order to insure uniformity in the application of the coat. Following the application of the second coat, the pieces of leather still in stretched condition on the frames are manually introduced into drying ovens where they are baked for periods of time varying from eight to ten hours or even more. In accordance with the usual practice, these ieces of leather are then sub'ected to the irect rays of the sun in open elds, the placing of the leather-carrying frames in rows and the transportation thereof being largely a matter of hand labor. If the weather conditions be favorable this solarizing operation may be completed in seven or eight hours. However, it is a common experience among patent leather manufacturers to have to carry all of the leather in from the field before the completion of the solarizing operation because of threatening weather conditions, since the damage to varnished surfaces caused by rain is so considerable, especially if it occurs early in the *day while the varnish coat is still soft, as to necessitate revarnishin'g all of the damaged pieces. In any case transportation of the pieces of leather to and from the solarizing field is a source of very considerable expense. More recently, it has been proposed to utilize artificial sources of ultra-violet radlation to cure the tackiness which still remains even after the thorough baking of the varnished surfaces in the baking ovens.

It is an object of this invention to provide articles of manufacture, such as pieces of leather, with varnish coats (thoroughly dry and free from undesirable tackiness) in such a way as to minimize handling or manipulatlon of the articles, whereby very substantial economies may be effected in the manufacturing operations, and to provide a suitable apparatus for the carrying out of the necessary operations. To these ends and in accordance with an lmportant feature of the invention there is provlded a conveyor mechanism constructed and arranged for presenting articles to be treated to varnish-applying means, then to varnish-drying means, and finally to means servmg as a source of ultra-violet radiation, the arrangement being such that pieces of Work are passed continuously in succession from one treating station to another without intermediate handling or manipulation of any klnd, thereby obviating the laborious andtlme-consuming work required in connection with prior constructions, and keepmg the work-treating means at the various stations working at capacity. In the illustrated construction, spraying means are employedfor applying two coats of varnish in succession to pieces of work during movement of the conveyor mechanism, each piece of work being passed through a drying chamber'or oven subsequently to the application of each coat of varnish. Following the dry ng of the last coat of varnish on given pleces of work, the latter are subjected while in place on the conveyor to ultraviolet radiation furnished by a battery of quartz mercury vapor lamps to effect a curing of the varnish surface whereby undesirable tackiness of the surface may be caused to disappear.

The method of this invention, by which varnished surfaces on articles of' manufacture are secured by applying and drying coats of varnish and subsequently curing the varnished surfaces by ultra-violet radiation, is characterized by the simultaneous subjection of some of the ieces of Work to varnish-applying operatlons, others to varnishdrying operations, and still others to varnish-curing operations, while all of the pieces of work are being carried along continuously in succession as by a single conveyor mechanism. By this method of treatment production goes on as a continuous operation and substantial economies are effected by the speeding up of the operations. As it is now proposed to practice the method, pieces of work will first be sprayed with a 1 rst-coat preparation, then successively passed through a heated atmosphere and again sprayed to provide a coat of varnish, the pieces of varnished work being next passed successively and continuously through a heated atmosphere and into position for treatment by ultra-violet radiation.

These and other features and characteristics of the invention will be described in detail in the specification and pointed out more particularly in the appended claims.

The drawing is a schematic diagram of an elevation of a suitable apparatus for the practice of my invention.

In the drawings I have shown an endless conveyor 1 on which are mounted the stretchers 8 carrying the prepared hides 2.

Tank 4 contains a sizing varnish, nitrocellulose, for example, which is sprayed on to the hides through the nozzle 15. This sizing is then dried in the drying chamber or drier 5 which is heated by a suitable source of heat as indicated at 6 and is ventilated by fan 7 blowing air into the drier and out through the exhaust 8. The finishing varnish is then applied from the tank 9 through thespray nozzle 16, the tank 9 being in advance of the drier 5 in the direction of movement of the conveyor 1. The

hides then pass through a second drying chamber or drier 10 where they are subjected to a preliminary drying after which they pass under *the bank of silica tube mercury-arc lamps. Here the drying or curing of the varnished surfaces substan tially to reduce or to remove tackiness is accelerated, due to the high intensity, or large quantity, of ultra-violet light to the influence of which the varnish is exposed. By reason of the intensive treatment by ultra-violet radiation, the curing of the varnish surfaces is speeded up and results obtained in a time varying between a few minutes and a few 'hours (in accordance with the number of lamps employed in a given space) that have heretofore been obtained only after many hours of solarizing. This material reduction in the time required to achieve the curing of the varnish surfaces permits of the arrangement of the described means for applying and drying varnish coats with the objects in View of saving space and effecting a marked reduction in the amount of manual labor. Furthermore, the reduction in the curing time by ultra-violet light makes it practical and essary to produce the finished patent leather is cut down materially, for the expeditious handling of the hides from the time the first sizing is applied until the finishing varnish has been dried produces the finished product in much less time than is involved in the usual procedure. A large number of the steps in the handling of the hides during their treatment is saved by simultaneously subjecting different hides to different steps in the process while they are being carried.

on the conveyor.

I claim as my invention:

1. In leather varnish applying and drying apparatus, in combination, a mechanical conveyor, means for holding stretched hides on said conveyor, means for applying liquid varnish preparations to said hides, means for drying the varnish on the hides, and means for producing light rich in ultraviolet rays for treating the hides, the conveyor being operated to maintain a continuous succession of hides past the liquid applying, drying, and ultra-violet ray treating means.

2. In leather varnishing apparatus, in

combination, an endless conveyor, stretching racks thereon carrying prepared hides, a varnish tank, a sprayer nozzle connected to said tank and positioned to apply varnish to said hides when passing thereunder, a drier chamber positioned about said conveyorfor a part of its length, and a bank of fused quartz mercury-arc lamps positioned to subject passing hides to ultraviolet ray treatment, said endless conveyor having an upper run for moving along in a horizontal plane a continuous succession of hides past the varnishing, drying, and ultra-violet ray devices.

3. In leather varnish applying apparatus, in combination, a conveyor, stretching racks thereon for carrying prepared hides, a size tank, a nozzle connected with said tank and positioned near the path of the moving hides, a heat chamber positioned about said conveyor, a varnish tank and a nozzle connected thereto and positioned near the path of the moving hides, a heat chamber following said nozzle in the path of the moving hides, and a bank of fused quartz mercuryarc lamps positioned near the conveyor whereby the varnished hides are subjected to ultra-violet light.

4. In the manufacture of patent leather the method of applying and drying on prepared hides of sizing and varnishwhich comprises passing said hides successively under a spray of sizing, passing 'the sized hides to the influence of light rich in ultra-violet rays until the varnish is suflieiently dried for use.

6. In leather varnish-applying and drying apparatus a conveyor, means for holding stretched hides on said conveyor, means for applying a liquid preparation to said hides, means for heating said hides positioned in advance of said liquid-applying means in the direction of movement of said conve or, means for applying varnish to said ides positioned in advance of said heating means, a second means for applying heat to said hides positioned in advance of said varnish-applying means, and a source of artificial light rich in ultra-violet radiation positioned in operative relation to the hides on said conveyor and in advance of the second said heating means.

7 That improvement in methods of making varnished surfaces on hides by applying and drying diiferent varnish coats on the i hides and subsequently curing the varnished surfaces by ultra-violet radiation, which compr1ses simultaneously subjecting some hides to varnish-applying operations, others 4 to varnish-drying operations and still others to varnish-curing operations, while they are being passed along continuously in succession as on a conveyor.

Signed at Boston in the county of Suffolk 4 and State of Massachusetts, this 13th day of September, A. D. 1923. ELIAS LEAVENWORTH ELLIOTT. 

